JPH0971787A - Unleaded gasoline - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare an unleaded gasoline which has a low benzene content, possesses good response to an air-fuel ratio and can reduce the amt. of benzene discharged by using a base gasoline having a high octane no. and a low benzene content. SOLUTION: A cracked gasoline, prepd. by a fluid catalytic cracking process, in an amt. of 0 to 60vol% and 0 to 30vol% alkylate gasoline are incorporated into 20 to 60vol% base gasoline, prepd. by mixing a light fraction in the b.p. range from the initial b.p. to 80 deg.C with a heavy fraction in the b.p. range from 90 deg.C to the final point in a catalytically reformed gasoline, thereby preparing an unleaded gasoline having an octane no. of not less than 96.0 as measured by the research method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel unleaded gasoline, and more specifically, it uses a gasoline base material having a high octane number and a low benzene content, has good air-fuel ratio responsiveness, and reduces benzene emissions. It concerns unleaded gasoline.

[0002]

2. Description of the Related Art Since the regulation of the addition of lead compounds as octane number improvers, the development of unleaded high octane number gasoline has been desired.
In recent years, various materials have been proposed as high octane number base materials. However, gasoline, which is conventionally proposed or used and which is composed of a gasoline base material, is not sufficient in terms of drivability of a gasoline vehicle equipped with a catalytic muffler and pollution caused by exhaust gas and the like. That is, the reformed gasoline that is usually used as a gasoline base material contains a large amount of aromatic components such as benzene, toluene, and xylene, and these aromatic components are converted to benzene when burned in the engine. Since the concentration of benzene increases in the exhaust gas, it is harmful and adversely affects the human body such as suspected carcinogenicity and is not desirable. Particularly, benzene already existing in the aromatic component is easily discharged from the engine as an unburned component, and contributes to the benzene concentration in the exhaust gas by about 9 to 35 times as much as other aromatic components. On the other hand, as a method for purifying the exhaust gas, a method using a three-way catalyst has become mainstream in recent years. This method is extremely effective in reducing carbon monoxide, hydrocarbons and nitrogen oxides, but for all of these,
It is well known that high purification performance is exhibited only in a narrow range of air-fuel ratio (hereinafter referred to as air-fuel ratio). Normally, during the transient operation of the engine, the air-fuel ratio largely deviates from the proper range, but from the above point of view, this deviation can cause deterioration of exhaust gas. Therefore, in order to solve such a problem, it is necessary to improve the air-fuel ratio responsiveness.

[0003]

Under these circumstances,
The present inventors have paid attention to the octane number distribution in each fraction of the catalytically reformed gasoline used as a base material, and have conducted a study to find that the cutane fraction of the catalytically reformed gasoline has the lowest octane number around 20 to 40% by volume. It was found that there is a fraction, while a fraction with a high octane number is present on the high boiling point side. The present invention has been accomplished based on the above findings. That is, the present invention has a high octane number, using a gasoline base material having a low benzene content, the content of benzene harmful to the human body is low, and the air-fuel ratio responsiveness is good,
Further, it was made for the purpose of providing unleaded gasoline capable of reducing the emission amount of benzene.

[0004]

Means for Solving the Problems As a result of earnest research by the present inventors, by using the remaining fraction of the catalytically reformed gasoline excluding the fraction with a low octane number as a high octane number base material for gasoline, The present invention has been completed by finding that the object of the present invention can be effectively achieved. That is, the present invention relates to a gasoline base material having 20-60 volumes of a gasoline fraction obtained by mixing a light fraction having a boiling point of 80 ° C. to a boiling point of 90 ° C. and a heavy fraction having a boiling point of 90 ° C. %,
(A) Cracked gasoline obtained by the fluid catalytic cracking method 0 to
An unleaded gasoline having a research octane number of 96.0 or more, which is obtained by blending 60% by volume and (b) 0 to 30% by volume of alkylate gasoline.

Hereinafter, the present invention will be described in more detail. The gasoline base material used in the unleaded gasoline of the present invention is a mixture of a light fraction having a boiling point of 80 ° C. to a boiling point of 90 ° C. and a heavy fraction having a boiling point of 90 ° C. to the end point of a catalytically reformed gasoline. It will be. In the present invention, catalytically reformed gasoline means heavy naphtha having a fractional distillation range of about 40 to 230 ° C. in a hydrogen stream,
It can be obtained by carrying out reforming reactions such as isomerization, dehydrogenation, cyclization and hydrocracking at high temperature and high pressure. As the reaction catalyst used in the above catalytic reforming method, there is a bimetallic catalyst in which a metal such as rhenium, iridium, or germanium is added to platinum or platinum. The reaction can usually be carried out under the conditions of a reaction temperature of 450 to 540 ° C. and a reaction pressure of about 7 to 50 kg / cm ² . Examples of the main catalytic reforming process include a platform forming method, an ultra forming method, a reniforming method, a power forming method, a magna forming method, and a hood reforming method.

As described above, the present invention divides the catalytically reformed gasoline into three fractions, a light fraction (L.PG), an intermediate fraction (M.PG) and a heavy fraction (H.PG). , L / PG and H
-A high octane number base material (L + H) PG obtained by mixing with PG is used. That is, the catalytically reformed gasoline contains a large amount of high octane number components such as toluene and xylene, but there is a fraction having the lowest octane number near the cut fraction of 20 to 40% by volume, while the high boiling point side. Aromatic components having a high octane number of 100 or more in the research method are concentrated in the area. From this, it is possible to use the high boiling point fraction (H · PG) of catalytically reformed gasoline as the high octane number base material.
・ PG alone has the drawback of having a high boiling point. Therefore, in the present invention, the remaining fraction excluding the middle distillate having a low octane number (cut fraction near 20 to 40% by volume, M · PG), that is, (L + H) PG is used as a high octane number base material for gasoline. Using.

High octane number base material [(L + H) PG]
Specifically, the middle distillate (M · PG) has a boiling point of 80 to 90.
It can be obtained by cutting at ℃. (L + H) PG obtained by such a method has a research octane number of 3 as compared with the original catalytically reformed gasoline before fractional distillation.
It is ~ 6 high, and the motor method octane number is 2-5 high. The (L + H) PG contains benzene at a low value of about 1% by volume. Furthermore, the resulting high octane number base material has a uniform octane number distribution for each fraction. In the present invention, the M / PG of the catalytically reformed gasoline is cut at a boiling point of 70 to 100 ° C, that is, L / PG from the initial boiling point to 70 ° C and the H / PG from 100 ° C to the end point are mixed. It is preferable to obtain a gasoline base material obtained from the above because the octane number can be further increased and the benzene content can be further reduced. Increasing the boiling point range of the above M / PG will result in (L + H) PG
Although it is effective to raise the octane number of (1) to a little, it is not preferable because the yield of (L + H) PG as a gasoline base material is lowered.

The unleaded gasoline of the present invention comprises 20-60% by volume of the above gasoline base material, (a) 0-60% by volume of cracked gasoline obtained by the fluid catalytic cracking method, and (b) 0-30% by volume of alkylate gasoline. %, And has a research octane number of 96.0 or more. That is, the unleaded gasoline comprises 20 to 60 gasoline base materials obtained by mixing a light fraction having a boiling point of 80 ° C. to a boiling point of 90 ° C. and a heavy fraction having a boiling point of 90 ° C. to the end point of a catalytically reformed gasoline fraction. capacity%
contains. If the content is less than 20% by volume, the effect of improving octane number and reducing benzene emission is insufficient,
When it exceeds 60% by volume, the low temperature startability is deteriorated and the aromatic content, which is said to have a bad influence on the rubber material of the fuel system, is increased, which is not preferable. From this point of view, the above-mentioned gasoline base material is preferably contained in the lead-free gasoline of the present invention in an amount of 20 to 50% by volume.

The cracked gasoline obtained by the fluid catalytic cracking method in the present invention is a cracked gasoline obtained by catalytically cracking a high boiling fraction of light oil or more in the presence of a solid catalyst in a fluidized bed. As the reaction catalyst used in this fluid catalytic cracking method, in addition to the conventionally used amorphous silica-alumina catalyst, a highly active zeolite catalyst mainly used in recent years can be used. Further, the fluid catalytic cracking process basically comprises a reaction tower and a catalyst regeneration tower, and the reaction is usually carried out at a reaction tower temperature of 470.
~ 550 ° C, regeneration tower temperature 600-650 ° C, reaction tower pressure
0.8-1.1 kg / cm ² , regeneration tower pressure 0.9-1.6 kg /
The condition is about cm ² . The main fluid catalytic cracking processes are air lift thermophore method, food reflow method, UOP method, shell two-step method, flexi cracking method, orthoflow method, texaco method, Gulf method, ultracat cracking method, alco cracking method, H
OC method, RCC method, etc. are mentioned. In the present invention, thermal cracking gasoline has an unsuitable quality such as octane number and stability, and hydrocracking gasoline is expensive in manufacturing cost. Preference is given to using. The alkylate gasoline used in the present invention is a high octane gasoline obtained by adding (alkylating) a lower olefin to a hydrocarbon such as isobutane, and this alkylation is carried out by a method usually used in the art. It is possible.

The unleaded gasoline of the present invention comprises a cracked gasoline obtained by a fluid catalytic cracking method, an alkylate gasoline, or a mixture thereof, which is added to the base material of the present invention.
It is compounded in an amount within the range of 40% by volume.
That is, in JIS K 2202, the 50% distillation temperature is 1
Although the temperature is specified to be 25 ° C. or lower, the 50% distillation temperature of the unleaded gasoline of the present invention is preferably 110 ° C. or lower in consideration of acceleration and warm-up during cold weather. On the other hand,
If the volatility is too high, bubbles of gasoline will be generated in the fuel supply system at high temperature, causing insufficient idling and poor acceleration due to insufficient fuel supply. In order to satisfy these requirements, in the present invention, it is necessary to mix the cracked gasoline or the like having low volatility. The cracked gasoline and alkylate gasoline are preferably 0 to 60% by volume, 0 to 30% by volume, and more preferably 5 to 60% in unleaded gasoline, from the viewpoints of ensuring the above-mentioned practical performance and optimizing the production cost. It is contained in an amount within the range of 5% to 30% by volume. The unleaded gasoline of the present invention has a research octane number (RON) of 96.0 or more, and a motor octane number (MON) of 86 or more from the viewpoint of preventing reduction in knock resistance at high speeds. preferable.

The unleaded gasoline of the present invention comprises, in addition to the above-mentioned base material, light naphtha and heavy naphtha obtained by fractionating a naphtha fraction by atmospheric distillation of crude oil, if necessary, and hydrogenating these. Desulfurized light naphtha obtained by refining, desulfurized heavy naphtha, cracked gasoline obtained by hydrocracking method other than fluid catalytic cracking method, polymerized gasoline obtained by olefin polymerization, straight chain lower paraffin hydrocarbon The isomerate obtained by isomerization of the above or a fraction thereof having a specific boiling point range, or a base material such as aromatic hydrocarbon, isopentane, or methyl tert-butyl ether (MTBE) can be blended. In the present invention, the above (L
By using the + H) PG base material, it is possible to produce unleaded gasoline which has a good responsiveness to the air-fuel ratio and can reduce the emission amount of benzene which is a harmful substance. That is, the unleaded gasoline of the present invention has the formula (1)

[0012]

[Equation 2](Where T_iIs the component i of the components that make up gasoline.
Represents the boiling point (℃) of V _iContains its component i in gasoline
Represents the amount (% by volume) that is present. In addition, n is a chromatograph
It represents the number of components confirmed by fee analysis. However,
Bright component is less than 10% by volume, ie ΣV_i≧ 90. )
The air-fuel ratio responsiveness index X represented by is 24.0 or less,
Formula (2) Y = 1.07BZ + 0.12TO + 0.11EB + 0.05XY + 0.03C9⁺A + 0.005 [1- (BZ + TO + EB + XY + C9⁺A)] (2) (wherein BZ, TO, EB, XY and C9⁺A is that
Benzene, toluene, ethylbenzene, xylene and
And the amount of aromatics containing 9 or more carbon atoms in gasoline
(Volume%) ) Exhaust gas index Y is 5.0
The following are preferable.

The condition represented by the above formula (1) relates to the component composition of gasoline, and the result of quantitative identification after separation and identification by the total composition analysis by the gas chromatograph method is the formula for calculating the air-fuel ratio responsiveness index of the formula (1). In the present invention, the value obtained by applying the above is preferably 24.0 or less. If the index X exceeds 24.0, the air-fuel ratio responsiveness may decrease. Further, the condition represented by the above formula (2) is also related to the component composition of gasoline as in the case of the above formula (1), and the result of separation and identification by the total composition analysis by the gas chromatograph method is used to calculate the result by the formula (2). In the present invention, it is preferable that the value obtained by applying the exhaust gas index calculation formula (1) is 5.0 or less. This index Y is 5.0
If it exceeds, the low pollution of exhaust gas may not be sufficiently achieved.

If necessary, the unleaded gasoline of the present invention may be appropriately blended with various additives within a range not impairing the object of the present invention. Examples of such additives include tertiary amyl methyl ether (TAM
E), ethyl tertiary butyl ether (ETB
E), tertiary amyl ethyl ether (TAEE)
Oxygen-containing compounds such as, phenol-based or amine-based antioxidants, metal deactivators such as Schiff-type compounds and thioamide-type compounds, surface ignition inhibitors such as organic phosphorus-based compounds, succinimide, polyalkylamines, Detergent / dispersant such as polyether amine, anti-icing agent such as polyhydric alcohol and ether, alkali metal or alkaline earth metal salt of organic acid, combustion improver such as sulfuric acid ester of higher alcohol, anionic surfactant, cationic Antistatic agents such as surfactants and amphoteric surfactants, antirust agents such as esters of alkenylsuccinic acid, discriminating agents such as quilizanin and coumarin, odorants such as natural essential oils and synthetic fragrances, and colorants such as azo dyes. Known fuel oil additives are listed, and one kind or two or more kinds of them can be added. Further, the amounts of these additives can be appropriately selected according to the situation.

[0015]

[Properties of fuel oil]

(1) Octane number (RON and MON) It was determined according to JIS K-2280. (2) Density It was determined according to JIS K-2249. (3) Distillation property It was determined according to JIS K-2254. (4) Component composition The content of each hydrocarbon in the fuel oil is determined by analysis of the total composition of gasoline by gas chromatography (in accordance with the Japan Petroleum Institute Method JPI-5S-33-90). The value was converted into volume% using the density of each hydrocarbon. Each component by this analytical method comes out in the order of boiling point.

[Evaluation of Fuel Oil Performance] (1) Air-fuel ratio responsiveness Displacement of 1500 cc, manual transmission,
Using multi-point injection engine, cooling water temperature is 25 ℃ and 80 ℃, rotation speed 1500rp
m, mission 4th speed, throttle valve 7%, and fuel injection amount fixed to the amount that makes the air-fuel ratio 15 From a steady state, the throttle valve is rapidly opened to 50% and at the same time the fuel injection amount is increased. The reaching air-fuel ratio was adjusted to 13, and the time to reach 90% was examined. (2) Benzene Concentration in Exhaust Gas According to TRIAS 23-991, "Gasoline vehicle idling, 11-mode exhaust gas test method, and SAE
Benzene concentration (% by weight) in hydrocarbon in exhaust gas according to the method described in Paper 920320
Was analyzed.

Examples 1 and 2 and Comparative Examples 1 and 2 Gasoline base materials having the properties and components shown in Table 1 were mixed in the proportions shown in Table 2 to prepare fuel oil, and their properties and performances were obtained. Was evaluated by the above method. Table 2 shows the results. Among the base materials used, the base material B is reformed gasoline obtained by a catalytic reforming method, and the base material A is an L-PG fraction having a boiling point of 80 ° C. from the initial boiling point of the base material B. A base material obtained by mixing H / PG fractions having a boiling point of 90 ° C. to the end point, and a base material A ′ is an initial boiling point of the base material B to the L / PG fraction having a boiling point of 70 ° C. and a boiling point of 100 ° C. to the end point. The base material C is a base material obtained by mixing the HPG fraction, and the base material C has a boiling point of 100 ° C. to the end point of H · P.
The base material is a G fraction, and the base material D is cracked gasoline obtained by the fluid catalytic cracking method.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

[Table 3]

[0021]

As described in detail above, a gasoline base material having a high octane number and a low benzene content can be obtained by mixing a light fraction and a heavy fraction of catalytically reformed gasoline. By using a gasoline base material, it is possible to obtain unleaded gasoline that has a low content of benzene, which is harmful to the human body, and has a good responsiveness to the air-fuel ratio while maintaining drivability, and that can further reduce the emission of benzene. You can

Claims (2)

[Claims] 1. A gasoline base material 20-60% by volume, which is obtained by mixing a light fraction from the initial distillation point to a boiling point of 80 ° C. and a heavy fraction from a boiling point of 90 ° C. to the end point of a catalytically reformed gasoline fraction. To
(A) Cracked gasoline obtained by the fluid catalytic cracking method 0 to
Unleaded gasoline having a research octane number of 96.0 or more, which is obtained by blending 60% by volume and (b) 0 to 30% by volume of alkylate gasoline. 2. Formula (1):(Where T_iIs the component i of the components that make up gasoline.
Represents the boiling point (℃) of V _iContains its component i in gasoline
Represents the amount (% by volume) that is present. In addition, n is a chromatograph
It represents the number of components confirmed by fee analysis. However,
The bright component is 10% by volume or less. ) Air-fuel ratio response
Responsiveness index X is 24.0 or less, and formula (2) Y = 1.07BZ + 0.12TO + 0.11EB + 0.05XY + 0.03C9.⁺A + 0.005 [1- (BZ + TO + EB + XY + C9⁺A)] (2) (wherein BZ, TO, EB, XY and C9⁺A is that
Benzene, toluene, ethylbenzene, xylene and
And the amount of aromatics containing 9 or more carbon atoms in gasoline
(Volume%) ) Exhaust gas index Y is 5.0
The unleaded gasoline according to claim 1, wherein: